Synchronizers are devices used in transmissions of motorized vehicles to facilitate the clash-free shifting of gears. On off-road type vehicles, such as agricultural and industrial equipment, the synchronizers are of a heavier construction in order to overcome the higher inertia forces of the transmission gears and traction clutch. With the increase in the overall size and weight of such equipment, there has been a demand to provide a more responsive synchronizer, one that has an increased energy capacity without further increasing its size.
Initial attempts to satisfy the industry demands have resulted in the production of synchronizers having a larger surface area. The larger surface area did increase the energy capacity of the synchronizers but also created increased bulk that caused assembly problems due to the space limitation of the transmission itself. Subsequent solutions attempted to retain the large frictional contact area while reducing the overall size of the synchronizer. Two such devices are taught in U.S. Pat. No. 3,286,801, issued to M. J. Maina in November, 1966 and U.S. Pat. No. 4,185,725, issued to R. J. Wojcikowski in January 1980. The Maina patent taught the use of primary and intermediate synchronizer elements to increase drag torque while the Wojcikowski patent utilized multiple cone shaped frictional surfaces. A third solution to the problem was taught in West German Pat. No. 1,755,457 which issued to M. Merjerle in March, 1971. This patent used self-energized balls retained in ramp recesses to provide axial movement between two of the synchronizer components to increase the synchronizer torque. None of these designs totally solved the industry problem.
Now an improved synchronizer has been invented for use in transmissions for motorized vehicles which is more responsive to shift demands.